Airbag module

An airbag module (100) comprising:

• i) a control unit;
• ii) a source of electrical current managed by said control unit;
• iii) a container (110) wherein a gas is stored under pressure, said container (110) comprising an outlet (111) sealed by a pierceable membrane (112);
• and
• iv) a hollow body (120) having a cavity (121), an inlet duct (122) and an outlet duct (123),
• wherein:
• said outlet (111) of the container (110) is fitted in said inlet duct (122) of said hollow body (120) and wherein an inflatable bag (130) is tightly assembled on said outlet duct (123) of the hollow body (120);
• the airbag module (100) further comprising an actuator assembly (140) configured to pierce open said membrane (112) sealing the container (110), said actuator assembly (140) comprising a piercing member (141) movably restrained to the body (120) so as to move a piercing end (141a) thereof beyond the pierceable membrane (112),
• characterized in that the actuator assembly (140) further comprises at least one linear shape memory alloy wire actuator member (143) that is electrically connected to the source of electrical current and operably restrained to said piercing member (141), and
• the overall configuration of the airbag module being such that by supplying an electrical current to said at least one linear shape memory alloy wire actuator member (143) this is heated at a temperature equal to or higher than its Austenite phase temperature (Af), undergoes a shortening and thus causes the piercing member (141) to cut the pierceable membrane (112) by moving therethrough, the linear shape memory alloy wire actuator member (143) returning to its previous size and shape upon cooling below its Martensite phase temperature (Mf).